The RMT union's complaints relate to the transfer of Piccadilly Line control-room services to a new centre in Hammersmith.
Transport for London plans to replace a number of separate control centres with a single one from 2017.
The Rail, Maritime and Transport Union says the move will cause job losses - and that there are also issues with rates of pay and the lack of "any meaningful offer for Service Control staff for the Olympic period."
More top news
Bright spells with rain, sleet and snow showers at the weekend.
As soon as the information went missing in early January, the Ministry of Justice say they launched an urgent investigation.
William & Son in London's exclusive Mayfair district was targeted by thieves reportedly carrying metal baseball bats.